WASHINGTON, November 18, 2013 – Access to improved sanitation can increase cognition in children, according to a new World Bank study. The study contributes to a growing body of research linking stunting and open defecation. Currently, more than 2.5 billion people worldwide lack access to toilets, and one billion people practice open defecation.

The recent World Bank policy research working paper, Effects of Early-Life Exposure to Sanitation on Childhood Cognitive Skills, released ahead of the first official UN World Toilet Day on November 19, studied the effects on childhood cognitive achievement of early life exposure to India’s Total Sanitation Campaign, a national scale government program that encouraged local governments to build and promote use of inexpensive pit latrines.

“Our research showed that six-year-olds who had been exposed to India’s sanitation program during their first year of life were more likely to recognize letters and simple numbers on learning tests than those who were not,” said Dean Spears, lead author of the paper. “This is important news -- the study suggests that low-cost rural sanitation strategies such as India’s Total Sanitation Campaign can support children's cognitive development.”

The results also suggest that open defecation -- going outside without using a toilet or latrine -- is an important threat to the human capital of developing countries, and that a program accessible to countries where sanitation development capacity is lower could improve average cognitive skills.

“Open defecation lies at the root of many development challenges, as poor sanitation and lack of access to toilets impact public health, education, and the environment,” said Jaehyang So, Manager of the World Bank’s Water and Sanitation Program. “This recent study joins a growing body of evidence indicating that open defecation harms infants and stunts the growth of young bodies and minds.”

A World Bank working paper released earlier this year found that children exposed to more fecal germs don’t grow as tall as other children with less exposure. Studies have shown physical height is an important economic variable reflecting health and human capital. However, differences in average height across developing countries are not well explained by differences in wealth, according to the report.

In particular, children in India are shorter, on average, than children in Africa who are poorer, on average, a paradox called "the Asian enigma," which has received much attention from economists (studies indicate a 5 year-old girl in India to be around 0.7 cm shorter than her counterpart in Sub-Saharan Africa). The World Bank paper, How Much International Variation in Child Height Can Sanitation Explain?” provided the first documentation of a quantitatively important gradient between child height and sanitation that can statistically explain a large fraction of international height differences (Unicef/WHO data show that open defecation levels in Sub-Saharan Africa were only 26% in 2011 compared to 50% for India).

"Within the triad of causes, food, care and environment, these papers provide additional evidence that inadequate sanitation is one of the important contributors to malnutrition, particularly in India,”said Bert Voetberg, Acting Sector Manager, South Asia Health, Nutrition and Population.